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NIHR Signal Keyhole surgery is more effective than physiotherapy for hip impingement

Keyhole surgery to reshape the joint surfaces in people with hip impingement improves hip-related quality of life more than physiotherapy.

In hip impingement, there is a painful restriction of the smooth movement of the ball of the femur inside the cup (acetabulum) of the pelvis. It mainly affects younger, active people. Observational studies have supported the use of keyhole surgery (arthroscopy), but there was a lack of high-quality evidence. This NIHR-funded study is the first trial to compare arthroscopy with optimal conservative care.

Both arthroscopy and physiotherapy led to improvements on a 100-point hip score by 12 months. However, arthroscopy caused an additional 6.8 points improvement, which is a clinically meaningful difference.

Further follow-up is needed to show that the effect is sustained. Nevertheless, this is the first good evidence for the effectiveness of arthroscopy, although it was more costly than physiotherapy.

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Why was this study needed?

Hip impingement is common, with one NHS trust estimating it affects 30% of people in the UK with higher prevalence among athletes. Different types are recognised, according to whether the shape of the head of the femur (cam impingement), the hip socket (pincer impingement) or both (mixed), are shaped slightly differently from normal. Over time this damages cartilage in the joint which causes pain and can lead to osteoarthritis.

Surgery to reshape the socket and repair damaged tissues has become an established treatment with around 2,000 procedures performed in the UK each year, mostly keyhole (arthroscopic). However, a 2014 Cochrane review identified no randomised controlled trials investigating arthroscopy for femoroacetabular impingement. The lack of good evidence prompted this randomised controlled trial comparing arthroscopy with the best available conservative care.

What did this study do?

The UK FASHIoN study was conducted in 23 UK hospitals. It allocated 348 people with femoroacetabular impingement (average 35 years) to either arthroscopy or a personalised physiotherapy programme. Randomisation was balanced according to the treatment centre and type of bone abnormality. If participants had impingement affecting both hips, the most affected side was treated. Patients with established osteoarthritis, prior hip fracture or other hip disease were excluded.

The physiotherapy programme involved personalised assessment, education, supervised physiotherapy and pain-relief when needed. It involved 6 to 10, face-to-face sessions over 12-24 weeks. Patients having arthroscopy received physiotherapy rehabilitation after surgery but delivered by separate physiotherapists.

Retention was high, 86% of patients received the allocated interventions and 92% completed quality-of-life questionnaires at 12 months. Assessors were unaware of the intervention received, which increases reliability in the results.

What did it find?

Arthroscopy gave greater improvement in hip-related quality of life at 12 months. This was measured using the international Hip Outcome Tool (iHOT-33) which measures pain, function and psychological effects on a 100-point score where lower scores indicate greater impairment. Physiotherapy improved from scores from 35.6 to 49.7 while arthroscopy improved them from 39.2 to 58.8. This gave a 6.8 difference in favour of arthroscopy (95% confidence interval [CI] 1.7 to 12.0) after adjusting for baseline score, gender, type of impingement and treatment centre. This exceeded the 6.1 point threshold for a clinically meaningful difference.

Planned subgroup analyses according to type of abnormality found a benefit of arthroscopy for cam impingement only (difference of 8.3, 95% CI 2.5 to 14.2) and not for pincer or mixed impingement. However, 75% of patients had cam impingement with smaller numbers in other groups limiting the reliability of this analysis.

Adverse effects were reported by 72% of the arthroscopy group and 60% of the physiotherapy group, with muscle soreness most common in both groups. Seven serious adverse effects were reported. Five of six in the arthroscopy group were related to treatment, mostly infections. The other two events, including one in the physiotherapy group, were not treatment-related.

There was no difference between groups in overall quality of life at 12 months, as measured using the EQ-5D or Short-Form Health survey (SF-12).

Average per person treatment costs were £3,042 for arthroscopy compared with £155 for physiotherapy. Despite 12 month benefits for hip-related quality of life, arthroscopy was not estimated to be a cost-effective use of NHS resources.

What does current guidance say on this issue?

NICE’s 2011 interventional procedures guidance advised that there is adequate evidence from non-randomised trial and case studies that arthroscopy for femoroacetabular impingement gives symptom relief in the short- to medium-term. However, they advised that there are well-recognised complications. NICE recommended that the procedure is carried out with normal arrangements for clinical governance, consent and audit with local review of outcomes.

Details of patients having these procedures should be added to the Non-Arthroplasty Hip Register (NAHR) run by the British Hip Society.

What are the implications?

This study provides the first good evidence for arthroscopy for femoroacetabular impingement. Without a placebo or sham procedure, it's difficult to rule out the possibility that receiving an intervention could have biased patient-reported improvements, and surgery was more costly than physiotherapy. Follow-up is needed to see whether improvements are sustained in the long-term to support the high cost of this treatment.

Why was this study needed?

Hip impingement is common, with one NHS trust estimating it affects 30% of people in the UK with higher prevalence among athletes. Different types are recognised, according to whether the shape of the head of the femur (cam impingement), the hip socket (pincer impingement) or both (mixed), are shaped slightly differently from normal. Over time this damages cartilage in the joint which causes pain and can lead to osteoarthritis.

Surgery to reshape the socket and repair damaged tissues has become an established treatment with around 2,000 procedures performed in the UK each year, mostly keyhole (arthroscopic). However, a 2014 Cochrane review identified no randomised controlled trials investigating arthroscopy for femoroacetabular impingement. The lack of good evidence prompted this randomised controlled trial comparing arthroscopy with the best available conservative care.

What did this study do?

The UK FASHIoN study was conducted in 23 UK hospitals. It allocated 348 people with femoroacetabular impingement (average 35 years) to either arthroscopy or a personalised physiotherapy programme. Randomisation was balanced according to the treatment centre and type of bone abnormality. If participants had impingement affecting both hips, the most affected side was treated. Patients with established osteoarthritis, prior hip fracture or other hip disease were excluded.

The physiotherapy programme involved personalised assessment, education, supervised physiotherapy and pain-relief when needed. It involved 6 to 10, face-to-face sessions over 12-24 weeks. Patients having arthroscopy received physiotherapy rehabilitation after surgery but delivered by separate physiotherapists.

Retention was high, 86% of patients received the allocated interventions and 92% completed quality-of-life questionnaires at 12 months. Assessors were unaware of the intervention received, which increases reliability in the results.

What did it find?

Arthroscopy gave greater improvement in hip-related quality of life at 12 months. This was measured using the international Hip Outcome Tool (iHOT-33) which measures pain, function and psychological effects on a 100-point score where lower scores indicate greater impairment. Physiotherapy improved from scores from 35.6 to 49.7 while arthroscopy improved them from 39.2 to 58.8. This gave a 6.8 difference in favour of arthroscopy (95% confidence interval [CI] 1.7 to 12.0) after adjusting for baseline score, gender, type of impingement and treatment centre. This exceeded the 6.1 point threshold for a clinically meaningful difference.

Planned subgroup analyses according to type of abnormality found a benefit of arthroscopy for cam impingement only (difference of 8.3, 95% CI 2.5 to 14.2) and not for pincer or mixed impingement. However, 75% of patients had cam impingement with smaller numbers in other groups limiting the reliability of this analysis.

Adverse effects were reported by 72% of the arthroscopy group and 60% of the physiotherapy group, with muscle soreness most common in both groups. Seven serious adverse effects were reported. Five of six in the arthroscopy group were related to treatment, mostly infections. The other two events, including one in the physiotherapy group, were not treatment-related.

There was no difference between groups in overall quality of life at 12 months, as measured using the EQ-5D or Short-Form Health survey (SF-12).

Average per person treatment costs were £3,042 for arthroscopy compared with £155 for physiotherapy. Despite 12 month benefits for hip-related quality of life, arthroscopy was not estimated to be a cost-effective use of NHS resources.

What does current guidance say on this issue?

NICE’s 2011 interventional procedures guidance advised that there is adequate evidence from non-randomised trial and case studies that arthroscopy for femoroacetabular impingement gives symptom relief in the short- to medium-term. However, they advised that there are well-recognised complications. NICE recommended that the procedure is carried out with normal arrangements for clinical governance, consent and audit with local review of outcomes.

Details of patients having these procedures should be added to the Non-Arthroplasty Hip Register (NAHR) run by the British Hip Society.

What are the implications?

This study provides the first good evidence for arthroscopy for femoroacetabular impingement. Without a placebo or sham procedure, it's difficult to rule out the possibility that receiving an intervention could have biased patient-reported improvements, and surgery was more costly than physiotherapy. Follow-up is needed to see whether improvements are sustained in the long-term to support the high cost of this treatment.

Background
Femoroacetabular impingement syndrome is an important cause of hip pain in young adults. It can be treated by arthroscopic hip surgery, including reshaping the hip, or with physiotherapist-led conservative care. We aimed to compare the clinical effectiveness of hip arthroscopy with best conservative care.
Methods
UK FASHIoN is a pragmatic, multicentre, assessor-blinded randomised controlled trial, done at 23 National Health Service hospitals in the UK. We enrolled patients with femoroacetabular impingement syndrome who presented at these hospitals. Eligible patients were at least 16 years old, had hip pain with radiographic features of cam or pincer morphology but no osteoarthritis, and were believed to be likely to benefit from hip arthroscopy. Patients with bilateral femoroacetabular impingement syndrome were eligible; only the most symptomatic hip was randomly assigned to treatment and followed-up. Participants were randomly allocated (1:1) to receive hip arthroscopy or personalised hip therapy (an individualised, supervised, and progressive physiotherapist-led programme of conservative care). Randomisation was stratified by impingement type and recruiting centre and was done by research staff at each hospital, using a central telephone randomisation service. Patients and treating clinicians were not masked to treatment allocation, but researchers who collected the outcome assessments and analysed the results were masked. The primary outcome was hip-related quality of life, as measured by the patient-reported International Hip Outcome Tool (iHOT-33) 12 months after randomisation, and analysed in all eligible participants who were allocated to treatment (the intention-to-treat population). This trial is registered as an International Standard Randomised Controlled Trial, number ISRCTN64081839, and is closed to recruitment.
Findings
Between July 20, 2012, and July 15, 2016, we identified 648 eligible patients and recruited 348 participants: 171 participants were allocated to receive hip arthroscopy and 177 to receive personalised hip therapy. Three further patients were excluded from the trial after randomisation because they did not meet the eligibility criteria. Follow-up at the primary outcome assessment was 92% (319 of 348 participants). At 12 months after randomisation, mean iHOT-33 scores had improved from 39·2 (SD 20·9) to 58·8 (27·2) for participants in the hip arthroscopy group, and from 35·6 (18·2) to 49·7 (25·5) in the personalised hip therapy group. In the primary analysis, the mean difference in iHOT-33 scores, adjusted for impingement type, sex, baseline iHOT-33 score, and centre, was 6·8 (95% CI 1·7–12·0) in favour of hip arthroscopy (p=0·0093). This estimate of treatment effect exceeded the minimum clinically important difference (6·1 points). There were 147 patient-reported adverse events (in 100 [72%] of 138 patients) in the hip arthroscopy group) versus 102 events (in 88 [60%] of 146 patients) in the personalised hip therapy group, with muscle soreness being the most common of these (58 [42%] vs 69 [47%]). There were seven serious adverse events reported by participating hospitals. Five (83%) of six serious adverse events in the hip arthroscopy group were related to treatment, and the one in the personalised hip therapy group was not. There were no treatment-related deaths, but one patient in the hip arthroscopy group developed a hip joint infection after surgery.
Interpretation
Hip arthroscopy and personalised hip therapy both improved hip-related quality of life for patients with femoroacetabular impingement syndrome. Hip arthroscopy led to a greater improvement than did personalised hip therapy, and this difference was clinically significant. Further follow-up will reveal whether the clinical benefits of hip arthroscopy are maintained and whether it is cost effective in the long term.
Funding
The Health Technology Assessment Programme of the National Institute of Health Research.

Expert commentary

Arthroscopic femoroacetabular impingement surgery has become increasingly commonly practiced but without a strong evidence base. This large randomised controlled trial compared hip arthroscopy with best conservative care and showed that quality of life improved more in patients treated with arthroscopy than in those treated with conservative care. It is not known, at this stage, what the long-term consequences of hip arthroscopy will be. This study did not compare hip arthroscopy with a placebo or sham surgical procedure, and in the light of evidence generated for knee arthroscopy and shoulder arthroscopy, the results of this trial should be interpreted with some caution.

Andrew Carr, Professor of Orthopaedic Surgery, Oxford

Expert commentary

Femoroacetabular impingement is a condition which can lead to osteoarthritis of the hip. This occurs due to an abnormal shape of the hip bone and/or hip socket, which creates friction in the hip joint with movement leading to cartilage damage. Keyhole surgery has been used to reshape the hip and repair the cartilage injury. This is the first study comparing the efficacy of surgical treatment (hip arthroscopy) with non-operative treatment. It is high-quality research which demonstrates better outcomes for patients who have had hip arthroscopy as opposed to physiotherapy.

Ernest Schilders, Professor of Orthopaedic Sports Medicine, School of Sport/ Leeds Beckett University